98 Bravada 4wd doesnt work

TheDozer · #1 10-29-2008, 08:35 PM

Ive got a 98 Bravada that I just bought and put a tranny in. Ever since the "service awd" light is on and the awd doesnt work. Anybody got any tips on diagnosing this?

Schrade · #2 10-29-2008, 10:22 PM

Go to a shop, see if you can get a print out of ALLDATA, or Mitchell's online, of diagnostic steps for 'Service AWD'.

Might have to offer a few bucks for it.

Post back on it...

MT-2500 · #3 10-30-2008, 08:59 AM

Quote:

Originally Posted by TheDozer

Ive got a 98 Bravada that I just bought and put a tranny in. Ever since the "service awd" light is on and the awd doesnt work. Anybody got any tips on diagnosing this?

As the light is telling you it needs serviced and checked out.

A transfer case scanner is needed to get codes and check out operation.

Always check fluid level and condition.
If it happened after a transmission replace check all wiring and wiring plugins and fuses.

Check for engine and transmission and transfer case codes.
Post back code no.

What transfer case does it have?

TheDozer · #4 10-30-2008, 11:07 AM

I have been through all the wiring with a fine tooth comb and turned up nothing. It has a NP163 T-case. I dont have a scanner to get the codes for the t-case but I did pull the codes for the engine and didnt have any. My owners manual says that t-case should be filled with ATF which I have since found out is incorrect, I replaced it with Autotrac-II yesterday which didnt change anything. It did however get driven about 200 miles with ATF in it.

MT-2500 · #5 10-30-2008, 11:42 AM

If you do not have the scanner.
You need to find a good repair shop with a transfer case capable scanner to test it and get codes.
Post back what codes they find.
And some one will help you on it.
With out codes and scanner data and scanner test on it is a crap shoot on fixing it.
Good Luck

Schrade · #6 10-30-2008, 11:49 AM

Quote:

Originally Posted by TheDozer

It did however get driven about 200 miles with ATF in it.

If this is accurate, then the fluid sensor might only have picked up the wrong viscosity, or the wrong chemical conductance of the fluid. I don't know how the sensor works.

And that's why you should get the diagnostic sequence 'Service AWD' system.

TheDozer · #7 10-30-2008, 07:44 PM

Quote:

Originally Posted by cbec1999

If this is accurate, then the fluid sensor might only have picked up the wrong viscosity, or the wrong chemical conductance of the fluid. I don't know how the sensor works.

And that's why you should get the diagnostic sequence 'Service AWD' system.

Would that cause the 4wd not to work at all? Which sensor would sense this, all of them? It has been driven for 2 days and approx 50 miles now with the right fluid in it.

blazes9395 · #8 10-31-2008, 12:59 AM

As long as there is fluid in the transfer case and the front differential, chances are you won't wreck anything with the service light on. In fact, some of the older models with the Auto-trac, AWD systems were filled with tranny fluid, or it was considered alright to use. With tranny fluid, these transfer cases tended to chatter. The blue Auto Trac fluid is now only reccomended, and solves any chattering, etc. You need a scanenr thats capable of scanning for these codes. A generic code reader will not work. After you get the codes read out properly, you can then narrow it down to where you have to be looking.

Schrade · #9 10-31-2008, 11:40 AM

Quote:

Originally Posted by TheDozer

Would that cause the 4wd not to work at all? Which sensor would sense this, all of them? It has been driven for 2 days and approx 50 miles now with the right fluid in it.

Don't know.

When I said fluid sensor, I was assumin' it's a fluid [level] sensor trippin' up the 'Service AWD' light. It might not even be a fluid sensor that's trippin' the code...

TheDozer · #10 11-02-2008, 10:13 PM

I cant explain it but the light just went off yesterday!

TheDozer · #11 11-09-2008, 12:55 AM

I knew it was too good to be true! The light came back on the other day. Im at a loss for what to try. Probably going to have to take it in and get it checked out.

Schrade · #12 11-09-2008, 09:55 PM

Quote:

Originally Posted by TheDozer

I knew it was too good to be true! The light came back on the other day. Im at a loss for what to try. Probably going to have to take it in and get it checked out.

Come now... You didn't think it just 'went away', did ya???

Since you're at a loss, try my suggestion: (3rd time)

Quote:

Originally Posted by cbec1999

Go to a shop, see if you can get a print out of ALLDATA, or Mitchell's online, of diagnostic steps for 'Service AWD'.

Might have to offer a few bucks for it.

Post back on it...

Quote:

Originally Posted by cbec1999

And that's why you should get the diagnostic sequence 'Service AWD' system.

TheDozer · #13 11-09-2008, 10:15 PM

Quote:

Originally Posted by cbec1999

Come now... You didn't think it just 'went away', did ya???

Since you're at a loss, try my suggestion: (3rd time)

Have you ever tried get them to give you this? I did, they wont give you anything for $20. The only place in town that can scan a service awd light is the dealer and they charge there full $99 diagnostic fee for it. I went to a local shop that said they would hook up a scan tool for the Awd light for $20 only to find out there scan tool only pulls service engine codes.

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